Model 646 spitting particulate at cylinder

[christy]

Revolver is "spitting" a stinging particle out both sides when firing any style of round.
Have had complaints from shooters to my left and right and have experienced same when others were shooting this gun.
Not a gun wrench but am of the opinion that it may be the cylinder/forcing cone gap, or a timing issue, or when locked up an alinement issue with the bores of the cylinder and the barrel bore.
How does one identify the culprit?
And if a positive issue is found how is it ameliorated?
Or am I sending it back to S&W?
Tried to contact them via email and got "zero" response to date, it's been a week today.
Thank you for your time...

 

[christy]

Revolver is "spitting" a stinging particle out both sides when firing any style of round.
Have had complaints from shooters to my left and right and have experienced same when others were shooting this gun.
Not a gun wrench but am of the opinion that it may be the cylinder/forcing cone gap, or a timing issue, or when locked up an alinement issue with the bores of the cylinder and the barrel bore.
How does one identify the culprit?
And if a positive issue is found how is it ameliorated?
Or am I sending it back to S&W?
Tried to contact them via email and got "zero" response to date, it's been a week today.
Thank you for your time...

 

[BlueMax_VMF114]

Hey,Sounds like it might be ammo junk being shot out the sides.my 357 does this sometimes,flame and powder out the sides and forward.....maybe it is a little gap between lock up?? maybe smith will have something for ya.

 

[2hawk]

Question is, is it spitting lead or just unburnt powder? Lead would indicate a timing issue requiring repair.

Unburnt powder is normal. Revolvers have the gap at the cylinder/barrel, and some ejecta is normal.

Maybe I am moving into old fartism faster than I think, but I have noticed lately that a lot of the younger and new shooters where I go have absolutely no knowledge of revolvers (not saying that this is the case here), and don't recognize something like flames coming from the bc gap to be normal.


"Wow, you got fire coming from your gun!"

 

[Match10]

If it is out of BOTH sides at the same time, it's simply powder residue and part-and-parcel of it being a revolver.

 

[BlueMax_VMF114]

Hey im an old fart too...hope ya didnt mean me as young.and yes all ive ever shot is wheel guns,and 1911s
my 44 puts on the best fire show

But i could see the Glock kids as not knowing a wheel gun shoots,and makes lots of smoke and noise......

 

[Wheelgunner840]

Hi christy, welcome to the forum.

You have named most of the usual suspects as far as the cause of "spitting". If it is indeed lead, you might want to call S&W customer service. Tell them the problem, and they will most likely send you a shipping label to send the gun in. Have you tried different brands of ammo yet to see if the problem is persistant?

Give the ammo change a try first, then contact S&W customer service.

WG840

 

[okie john]

As people have pointed out, blast at the cylinder gap is normal with any revolver. The 40 S&W is loaded pretty hot, so the blast may be a little more pronounced with it than with other cartridges, especially older ones.

Until the stuff starts hitting you, you don't have a problem.


Okie John

 

[j38]

I had a Centennial once that spit lead like crazy. I checked the B/C gap and it was about 3 times larger than it should be. When I called the factory, they sent me a label and I returned the gun. It came back in about a week with a new barrel.

Good luck with yours,

Jerry

 

[Dale53]

I have seen factory revolvers without a tapered entry at the entrance to the barrel (forcing cone). It was easily remedied with a Brownell tool made for the purpose (I tried to Google Brownell's for a link but can't find it there - they have them as my buddy has one for different calibers and we have used it more than once).

Inspect the forcing cone. I have seen Rugers, Smiths, and Colts with a "less than perfect" forcing cone.

If that is the case, call Smith and send it back for a fix. It's really not a laughing matter. I had a close friend that buried a rather large piece of bullet jacket in his face from the barrel/cylinder gap in HIS OWN revolver (.41 Magnum - 57 Smith). Fortunately, it healed nicely...

Dale53

 

[christy]

Thank you for your timely, comfirming responses.
To be clear all fellows involved are mid to late 50's, myself included.
All in fact are shooting revolvers although some of them aren't S&W (the rest of us don't raze them too awfull much).
The typical S&W attendance for us is models 67, 686, 686+, 625, and 610, none of which exhibt the amount of, or "sting" to the bystanders like the 646.
Yeah we kind of have a thing for S&W round and rounders, as we are all challenged by our "roundness".
We are quite used to the ejecta from the cylinder forcing cone gap from all the weapons, just not the zapping we are getting from the 646.
Round is Speer 155gr JHP, LE practice ammo on full moons.
And it is quite accurate at 25yd and in for all.
Just has this quirk of "the sting" and some were conjecturing there might be an issue.
What is the correct cyclinder gap?
How does one determine timing or bore alinement?
So we are doing our research, here and elsewhere, and again I say:

Thank You.

Christy

 

[scott625b]

Does this occur during both single action and double action? If it only happens during double action, you may have a timing issue. If it happens during both, it is probably a powder residue.

 

[s&wchad]

I'm not a gunsmith but I'll tell you what I think I know.

Barrel cylinder gap should be somewhere in the .003" to .007" range, although a .22 revolver that S&W serviced for me came back with a .010" gap and it shoots fine. The bigger the gap, the more it spits.

Alignment is checked with a precise fitting rod that drops down the bore and into the cylinder - a gunsmith can check it for you.

The forcing come is a funnel shaped cut at the back of the barrel that guides the bullet into the rifling - make sure it's been cut.

If the cylinder stop (that little piece that pops up from the bottom of the frame window and aligns the cylinder) engages the cylinder notches before the hammer falls in DA or when the hammer is cocked in SA, the timing is OK - check each one. You should place fired cases in every other chamber and cycle the action slowly when checking.

If the cylinder has excessive rotational play when the hammer is down and the trigger held back, the gun can shave lead. A little play is OK. Endshake (front to back movement of the cylinder) can also cause problems, but .001" or .002" is fine.

I'd phone S&W. It is covered under the lifetime warranty and you might as well let them look at it.

 

[RightWinger]

I hope this isn't normal with 646's, because I just bought one and its on its way to me sometime this week.....ha

 

[TSQUARED]

I have two of the S&W 646 and they perform superbly. Howver I do use relatively light reloads - 155 to 180 gr. jacketed or plated bullets at ca 750 fps. You might be expereincing normal operation with those full powwer loads.